Hello. First time posting. Looking for some help. I have a 98' fleet wood double wide. The roof was installed 2yrs ago. 25 yr 3 tab shingle over style ridge. Recently noticed water stains on the inside along the ceiling where the trailer meets and some stains showing up down the wall along the same center area. I previously had 2-3 turtle vents but when the roofer replaced the roof he went back with 2-3 off ridge style vents on the back and no vents on the front. I called the roofer out and he said it's not the roof you have a moisture problem and need to add 2-3 off ridge vents on the front to solve the problem. When he removed some ridge cap shingles there was nothing over the whole where trailer meets there was just the plastic barrier that goes down in-between the trailer from floor to ceiling. Does anyone know if it is code to install something over the hole that runs along the ridge to prevent water penetration if it should get in at the ridge? I was told there is usually a valley type metal used? Looking for any guidance to resolve my issue. Thanks.